Curated OER
Investigating Segments in a Right Triangle
High schoolers explore the concept of right triangles as they construct a right triangle using Cabri Jr. Learners find the midpoint of the hypotenuse and construct a line from the midpoint to the vertex of the right angle. They then...
Curated OER
Measuring Angles in a Triangle
High schoolers investigate the sum of the measures of the angles of a triangle. They draw a triangle and measure the interior angles. Using Cabri Jr., learners find the sum of the measures of the interior angles. The lesson provides an...
Curated OER
Congruent Triangles
Students identify properties of triangles. In this geometry lesson, students differentiate between similar and congruent triangles. They use the umber of sides to help define the angle of the polygon.
Curated OER
Similar Triangles and Proportions
Pupils investigate similar triangles and proportions as they make conjectures about the length of sides of similar triangles. For this lesson plan, have your class construct similar triangles using Cabri Jr so that they share a common...
Curated OER
Triangle Inequality Theorem
High schoolers investigate the relationship between angle measures and sides of a triangle and the relationships among the three sides of a triangle. The use of technology (Cabri, Jr.) allows learners to make and test conjectures as they...
Curated OER
30-60-90 Right Triangles in Cabri Jr.
Young mathematicians draw and label right triangles using Cabri Jr. technology. They create other special right triangles and identify the length of the hypotenuse and each leg. High schoolers explore the ratios to determine how the...
Curated OER
Ratios in Right Triangles
Learners calculate the sides of right triangles in this trigonometric ratios lesson. They use Cabri Jr. software and TI-83 or TI-84 calculators to find the side lengths and their ratios to each other for various triangles. The provided...
Illinois State Board of Education
Geoboard Areas
Middle school geometers determine the area of a shape on a geoboard or dot paper and draw figures that meet given area conditions. Working as a class, they develop and discuss various ways to draw geometric shapes with specified...
Curated OER
Triangle Trigonometry IB Packet
In this trigonometry worksheet, students use triangle trignometry to solve problems in order to find the missing length, angle, or area of the triangle. The one page worksheet contains five ...
Curated OER
Midsegments of Quadrilaterals
High schoolers explore the concept of quadrilaterals as they find the midsegments of quadrilaterals using Cabri Jr. on a graphing calculator. They find midpoints, slopes, angles, and distances of lines and angles.
Mathematics Vision Project
Module 5: Modeling with Geometry
Solids come in many shapes and sizes. Using geometry, scholars create two-dimensional cross-sections of various three-dimensional objects. They develop the lesson further by finding the volume of solids. The module then shifts...
Concord Consortium
Divisions
Divide and conquer the geometry problem. Young scholars consider how to subdivide triangles into smaller ones that have equal areas. They must apply their knowledge of medians to help accomplish the task.
Mathematics Vision Project
Circles: A Geometric Perspective
Circles are the foundation of many geometric concepts and extensions - a point that is thoroughly driven home in this extensive unit. Fundamental properties of circles are investigated (including sector area, angle measure, and...
Illustrative Mathematics
Extensions, Bisections and Dissections in a Rectangle
Gaining practice in translating a verbal description into a diagram and then an equation is the real point of this similar triangles exercise. Once the diagram is drawn, multiple methods are provided to reach the conclusion. An effective...
EngageNY
Ptolemy's Theorem
Everyone's heard of Pythagoras, but who's Ptolemy? Learners test Ptolemy's Theorem using a specific cyclic quadrilateral and a ruler in the 22nd installment of a 23-part module. They then work through a proof of the theorem.
Curated OER
Sphere Dressing
Geometric design makes a fashion statement! Challenge learners to design a hat to fit a Styrofoam model. Specifications are clear and pupils use concepts related to three-dimensional objects including volume of irregular shapes and...
Curated OER
Practice: Word Problems
Congratulations, you've just hit the word problem jackpot! Covering an incredible range of topics from integers and fractions, to percents, geometry, and much more, this collection of worksheets will keep young mathematicians...
Curated OER
Classifying Triangles Based On Properties of Angles
The interactive lesson plan featured here calls for the use of a Smartboard for sorting and classifying shapes. Then, pupils discuss the rules they followed for sorting their shapes, particularly focusing on the properties of angles....
Curated OER
Areas of triangles, trapezoids, and rhombi
Students solve geometry problems. In this area and perimeter instructional activity, students use formulas to solve problems from the textbook.
Curated OER
Review of Triangles
Students investigate the Pythagorean Theorem. In this geometry instructional activity, students define angles and sides of right triangles. They calculate the area and surface area using formulas derived by the Pythagorean Theorem.
Curated OER
Review Geometry - Week 8 (Triangles)
In this triangle worksheet, students use similar figures to find the length of one side of two similar triangles. They find the area of a triangle inscribed in a rectangle. This two-page worksheet contains eight problems.
Curated OER
Triangles
In this triangles worksheet, 10th graders solve 10 different problems that include determining the measurement of various angles. First, they determine the area of a triangle illustrated on the sheet. Then, students use the picture to...
Curated OER
Seven Sets of Area Problems
For this area worksheet, students solve for the area of rectangles, parallelograms, triangles, trapezoids, kites, regular polygons, circles, and surface area. The worksheets is divided into seven different sets of problems.
Curated OER
Perimeter and Area
Seventh graders develop strategies for finding the perimeter and area of large geometric figures. Through lecture and guided practice, 7th graders practice the strategy of dividing a geometric shape into smaller more manageable shapes...